The present invention relates in general to interior security devices for doors, and more particularly to an interior security device for double doors.
Heretofore, double doors were secured from the inside of a building by a bar extending across u-shaped brackets fixed to the respective double doors. The patent to Marshall U.S. Pat. No. 694,975, issued on Mar. 11, 1902, for Shutter Holder, discloses a link with longitudinally spaced, transversely extending slots at the ends of the link for placement behind rings of double shutters. It was heretofore known to employ a metal plate with longitudinally spaced, transversely extending slots for placement between the interior portions of double doors and interior knobs fixed to respective adjacent double doors.
In the patent to Cassileth U.S. Pat. No. 2,151,587, issued on Mar. 21, 1939, for Door Handle Lock, there is described a flat, resilient plate member with loops at the ends thereof for placement between adjacent doors of an automobile and the door handles on the respective doors. The patent to Jenks U.S. Pat. No. 2,899,229, issued on Aug. 11, 1959, for Child Proof Cabinet Lock, shows a coil spring with hook ends to encircle door operating hardware.
Other patents of interest are:
U.s. pat. No. 2,532,586; PA1 U.s. pat. No. 3,059,952.
The security devices for double doors heretofore known were not adaptable for accommodating variations in distances between the adjacent door knobs. Additionally, merely raising the plate of the security device resulted in the removal of the security device from the locking position.